Mechanism for advancing and retracting safe



June 26, 1962 c. PANTER 3,040,839

MECHANISM FOR ADVANCING AND RETRACTING SAFE EDGES CARRIED BY ELEVATOR DOORS Filed Nov. 25, 1957 5 Sheets-Sheet 1 OOOOO G INVENTOR.

CAR L PAN FER \ATTOR YS Ji'i-g. JZ'

June 26, 1962 c PANTER 3,040,839

MECHANISM FOR ADVANCING AND RETRACTING SAFE EDGES CARRIED BY ELEVATOR DOORS Filed Nov. 25, 1957 5 SheetsSheet 2 INVENTOR.

CARL PANTER ATTORNEYS June 26, 1962 c. PANTER 3,040,839

MECHANISM FOR ADVANCING AND RETRACTING SAFE EDGES CARRIED BY ELEVATOR DOORS 5 Sheets-Sheet 3 Filed Nov. 25, 1957 I48 INVENTOR BY CARL PANTER ATTOREYS f June 26, 1962 c. PANTER 3,040,839 MECHANISM FoR ADVANCING AND RETRACTING sAFE EDGES CARRIED BY ELEVATOR DOORS Filed Nov. 25, 1957 5 SheetsSheet 4 INVENTOR. CARL PANTER Z=."z-g. .2 BY

ATTOR N EYS June 26, 1962 Filed Nov. 25, 1957 C. PANTER MECHANISM FOR ADVANCING AND RETRACTING SAFE EDGES CARRIED BY ELEVATOR DOORS 5 SheetsSheet 5 ATTORNEYS 3,040,839 Patented June 26, 1962 ice 3,040,839 MECHANISM FOR ADVANCING AND RETRACT- ING SAFE EDGES CARRIED BY ELEVATOR DOORS Carl Panter, Toledo, Ohio, assignor to Toledo Scale Corporation, Washington Township, Ohio, a corporation of Ohio Filed Nov. 25, 1957, Ser. No. 698,492 6 Claims. (Cl. 187-52) Many power operated doors of elevator cars are equipped with so-called safe edges which stand along the front margins of the doors and which, when they encounter persons or. other obstacles as the doors are closing, activate mechanisms that stop or reverse the closing movements of the doors.

It is desirable that suchsafe edges be carried somewhat in advance of the forward margins of the doors while the doors are closing but it is undesirable that the safe edges narrow the door openings when the doors are fully open and it is undesirable that the safe edges prevent the doors, as distinct from the safe edges, from completely closing.

It is a general object of this invention to provide improved mechanism for advancing and retracting a safe edge.

More specifically it is an object to provide improved mechanism which so connects a safe edge to the door by which the safe edge is carried that the safe edge is moved differentially in respect of the door movement as the door approaches or leaves fully open or completely closed position.

A further object is to provide improved safe edge protruding and retracting mechanism which requires no separate motorization and which consumes very little of the power by which the door is moved.

Another object is to provide an improved safe edge which upon encountering a person will touch the person softly and lightly and will act instantly to cause the door by which it is carried to be immediately withdrawn.

A further object is the provision of an improved safe edge advancing and retracting mechanism which, though of ample strength, does not require a noticeable increase in spacing between the car door which carries the mechanism and hatchway doors and walls which are outside of and conceal the mechanism.

Another object is to provide safe edge advancing and retracting mechanism which can be adjusted accurately with a minimum of such interaction as might cause the making of some adjustments to vitiate other adjustments previously made.

And still another object is to provide improved safe edge mechanism that is inconspicuous and operates silently, smoothly and reliably to keep the safe edge at maximum advance during most of the closing movement of the door by which it is carried.

Other objects and numerous advantages of the invention will be apparent upon perusal of the following specification as illustrated by the drawings, in which:

FIG. I is a View as seen from the inside of an elevator car showing the forward margin of a car door with a safe edge advanced as it is by the mechanism of this invention when the door is partially open;

FIG. II is a similar view with the safe edge retracted and the door completely closed;

FIG. III is a view of the safe edge advancing and retracting mechanism as it appears when the door is fully open and the safe edge fully retracted, as seen from the outer side of the car door, the mechanism being not con cealed by any hatchway door or wall, parts being broken out and parts being shown in dash lines;

FIG. IV is a fragmentary view showing some of the mechanism as it appears when the door is partially closed;

FIG. V is a fragmentary view showing some of the mechanism as it appears when the door is completely closed;

FIG. VI is a fragmentary view showing the manner in i which the mechanism illustrated by FIG. III can be inverted to be operated from a frame member above the car door;

FIG. VII is an enlarged fragmentary sectional view taken as indicated by the line VII--VII of FIG. III;

FIG. VIII is a similarly enlarged fragrnentary sectional view taken as indicated by the line VIIIVIII of FIG. III;

FIG. IX is a similarly enlarged fragmentary sectional view taken as indicated by the line IXIX of FIG. III a part being broken out;

FIG. X is a similarly enlarged fragmentary sectional view taken as indicated by the line X-X of FIG. III; and

FIG. XI is a further enlarged fragmentary view of a spider and cooperating members which perform important functions in the operation of the mechanism.

This specification and the accompanying drawings are intended to describe and illustrate a preferred form of the invention but are not intended to impose limitations upon the scope of the invention. i

The invention is applicable either to side opening doors or to center opening doors. FIGS. I and II illustrate a side opening car door 9 of an elevator car 10 as seen from the inside. The car door 9 carries a safe edge 11 which stands along the front margin of the car door 9 and which, when the car door is partially open, is advanced for a short distance, e.g. 1% inches more or less ahead of the front margin of the door, as shown in FIGS. I and IV. When the car door is completely closed the safe edge is retracted until, as shown in FIGS. II and V it protrudes only about of an inch, or less. When the car door is fully open the. safe edge is again retracted, as shown in FIGS. III and XI.

The construction of the safe edge itself is shown in- FIG. VII. The safe edge itself consists of a hollow semi cylindrical nosing 12 having rearwardly extending wings 1'3 and 14 that embrace a channel shaped metal strip 15 within which lies a bar 16, having cross sectional dimensions that are considerably smaller than the cross sectional dimensions of the channel shaped strip. The space between the channel shaped strip 15 and the bar 16 contains several sections of sponge rubber 17 or equivalent soft elastically deformable material, the sections functioning as soft springs. The nosing 12 with its wings 13 andv 14 may be made of medium soft rubber, e.g. 60 durom eter. The channel shaped strip 15 and the bar 16 may be made of aluminum alloy and the nosing 12, the channel shaped strip 15 and the bar 16 all may be formed by extrusions through properly shaped dies, the channel shaped strip 15 and the bar 16 being extruded with rearwardly opening undercut grooves which are utilizable' for receiving the heads of bolts or other fastening devices.

The safe edge as thus constructed stands along the forward margin of thedoor 9 from top to bottom. Because of the form and construction of the rubber nosing 12 and the interpositioning of the sections of elastically deformable spongy material between the channel shaped strip 15 and the bar 16, the safe edge 11 upon encountering a person as the door is closing touches the person softly and lightly. As the nosing 12 and the channel shaped strip 15 yield to the light touch, plungers 18 close or open one or more of a plurality of micro-switches that are mounted on the bar 16 at the rear of the safe edge to make or break circuits which cause the door to stop or reverse its movement. The circuits and the door operating mechanism controlled thereby are of conventional form and therefore are not described herein or shown by the drawings.

The safe edge advancing and retracting mechanism is carried on the outer side of the door 9 and is concealed when in use by hatchway walls and doors. The hatchway door at a floor where the elevator car door 9 opens and closes is operated to open and close in unison with the car door 9. Since various mechanisms for thus operating hatchway doors are known in the art and are usable in installations where the safe edge advancing and retracting mechanism of this invention is employed no hatchways or hatchway door or hatchway door operating mechanisms are described herein or shown by the accompanying drawings.

Secured to the outer side of the door 9 is a mounting strip 20 which extends vertically from the upper part of the forward margin of the door nearly to the bottom of the door and is provided with properly spaced holes for the reception of bolts or screws used in securing plates, brackets and other fittings and elements thereto.

, Mounted upon the mounting strip 20 adjacent its upper end is an upper fulcrum plate 21, the upper fulcrum plate 21 having vertically elongated openings 22 which receive bolts 23 projecting from the mounting strip 20 so that some vertical adjustment of the upper fulcrum plate 21 is permitted. Fulcrumed upon the upper fulcrum plate 21 is an upper bell crank lever 24 having a relatively short arm 25 which extends nearly horizontally when the safe edge 11 is retracted and a relatively long arm 26 which extends nearly vertically when the safe edge is retracted.

Mounted upon the mounting strip 20 adjacent its lower end is a lower fulcrum plate 27 upon which is fulcrumed a lower bell crank lever 28 having arms 29 and 30 which are counterparts of the short and long arms 25 and 26 of the upper bell crank lever 24.

The arms of the upper bell crank lever 24 are maintained parallel to the arms of the lower bell crank lever 28, as the levers pivot about their fulcrums 31 and 32, by means of a rigid drag link 33 which connects the power pivot 34, of the upper bell crank lever 24, to the power 7 pivot 35 of the lower bell crank lever 23.

The load pivot 36 of the upper bell crank lever 24 is pivoted to an upper bracket 37 which is fixed to the bar 16 which forms part of the structure of the safe edge 11 adjacent the upper end of the bar. Similarly, the load pivot 38 of the lower bell crank lever 28 is pivoted to a lower bracket 39 which is fixed to the bar 16 adjacent its lower end. Hence, when the rigid drag link 33 moves up and down the safe edge moves forward and back. The drag link and safe edge are vertical and parallel to each other in all positions of the bell crank levers.

To exert an upward pull upon the drag link 23 and thus tend to move the safe edge 11 forwardly and to keep the safe edge in forward position, even when closing movements of the door are accelerated and inertial forces are set up, a retractile helical spring 40 is anchored at its upper end to the door 10, its lower end being fastened to a lifting plate 41 which is mounted for vertical adjustmentupon the rigid drag link 33.

When the short arms 25 and 29 of the bell crank levers are nearly horizontal and the long arms 26 and 36- of the bell crank levers are nearly vertical the effective leverage of the weight of the rigid drag link is at its maximum and the lifting eifect of the retractile spring also is at its maximum because it is then that the spring is stretched to the greatest extent. As the short arms 25 and 29 of the'bell crank levers swing upwardly and forwardly and the long arms 26 and 30 of the bell crank levers swing downwardly and forwardly the effective leverage of the weight of the rigid drag link 33 diminishes while the effective leverage of the weight of the safe edge 11 and the parts carried thereby increases. Thus, as the leverage of gravitational forces tending to turn the bell crank 4?. levers counterclockwise increases, the upward pull of the retractile spring decreases, and the net force acting to move the safe edge forwardly and keep it in forward position remains more nearly uniform than either the force exerted by the spring alone or the force exerted by gravity alone.

The tension of the retractile spring 49 can be adjusted by adjusting the lifting plate 41 along the drag link until the force exerted by .the spring and the loading of the bell crank levers are coordinated to adjust to proper value the net force acting to move the safe edge forwardly.

The safe edge 11 can be retracted notwithstanding the yieldable pull of the spring 40 by positively swinging the bell crank levers clockwise. FIGS. III and XI show the mechanism in the position that it assumes when the safe edge is retracted.

In the form of device illustrated, a many armed spider 42 is rockably mounted on a pintal 43 which is fixed upon the door 9 adjacent the lower forward corner of the door. One of the arms of the spider 42 carries a horizontally directed push screw 44 which, when the spider rocks counterclockwise, pushes against a lug 45 that is fixed to the lower bell crank lever '28 and extends downwardly from the fulcrum 32 of the lever. The lug'45 may be equipped with an anti-friction roller to be engaged by the end of the screw 44.

Another arm of the spider 42 carries a wheel 46 which, as the door It] moves into fully open position, rolls up a ramp 47 that is fixed to the sill 48 of the door frame. When the wheel 46 rolls up the ramp 47 the spider 42 is rocked counterclockwise and the push screw 44 acting through the lug 45 positively swings the lower bell crank lever clockwise (as seen in FIG. III) pulling the drag link 33 downwardly to stretch the spring 40 and swing the upper bell crank lever clockwise thereby translating the safe edge 11 backwardly, until when the wheel 46 has reached the top of the ramp 47 the safe edge has been retracted until it is nearly flush with the forward edge. of the door 9.

The arm of the spider 42 which carries the wheel 46 has a downwardly projecting lug 49 having a threaded hole into which a threaded pin 50 is screwed. The pin 50 projects into a compressible spring 51. The spring 51 is compressed between a nut 52 and an abutment 53 on the mounting strip 20, through which the pin passes freely. By turning the nut 52 the spring 51 may be prestressed so that it normally holds the wheel 46 above the sill 48 after the wheel leaves the ramp 47.

The electric circuit which is made and broken by the micro-switches 19 is carried by conductors in a cable 57 one end of which is fastened to a switch box 58 that moves with the safe edge 11, the part adjacent the switch box 58 being looped upwardly and then clipped to the door 9 in such manner as to allow the safe edge to move relatively to the door. The cable 57 has a bight which takes around a pulley 54 that is carried by a beam 55 one end of which is hingedly connected to the spider 42. The other end of the cable 57 is fastened to the elevator car so that as the door 9 closes the pulley 54 and the beam 55 are raised. The weight of the pulley 54 and the beam 55 acting upon the bight of the cable 57 that takes around the pulley 54 keep the bight of cable taut in all positions of the door so that it cannot writhe into and foul the mechanism.

The beam 55 carries a roller 59 which lies beneath the end of a cap screw 60 that is threaded upwardly through an arm of the spider 42 and is equipped with a lock nut 61. The cap screw 60 is backed down into position to be engaged by the roller 59 when the door 9 is nearly closed. When the door moves to completely closed position while the end of the cable 57 that is fastened to the car does not move with the door, the bight that takes around the pulley 54 rises, as the center portion of a catenary does when the ends of the catenary are moved apart. The rising bight pulls the pulley 54 upwardly and the roller 59 presses upwardly on the cap screw 60 thus turning the spider 42 counterclockwise. The cable 57, the pulley 54 and the lever 55 thus function during the final closing movement of the door to cause the safe edge to be retracted, in approximately the same way as the ramp 47, the wheel 46 and the spider arm that carries the wheel function during the final opening movement of the door.

Screwing the cap screw 60 up or down adjusts the width of the space between the door and jamb when the safe edge begins to retract. Adjustments of the cable actuated portion of the retracting system do not affect adjustments of the ramp operated portions. Hence, the adjustments may be quickly and accurately made without fiddling between adjustments of the cable actuated portion and adjustments of the ramp actuated portions.

It is to be noted that the cable 57 has the dual functions of carrying current to actuate mechanism for stopping and reversing door closing movements and pulling the safe edge back as the door completes its closing movement and that the pulley and lever perform the dual functions of taking up slack in the cable even before the roller 59 touches the cap screw 60 and then quickly retracting the safe edge at the end of the doors closing movement.

The safe edge advancing and retracting mechanism can be inverted, the ramp being secured to the member above the door as shown in FIG. VI. With the safe edge advancing and retracting mechanism inverted, ramps, or cams, can be used to actuate the retracting mechanism when the door nears completely closed position as well as when the door nears fully opened position. The use of two ramp cams above the door is feasible because there is no possibility that one of them might be a stumbling block to passengers. It is possible to use two ramps attached to the door sill if they are sunk into a slot so that they do not project above the upper surface of the sill. Employment of the distinct cable actuated retracting mechanism and ramp actuated retracting mechanism as shown in FIG. 'III is, however, much to be preferred when a ramp is used at the door sill.

When the actuating means for safe edge retraction utilizes only the ramp cams 47 as shown in FIG. VI, certain elements of the mechanism are modified from the form employed in FIGS. III, IV, V and XI. These modifications reside in the elimination of the cable actuated portions and the adaptation of the unit for inverted gravitational forces. In FIG. VI like reference characters have been applied to elements which have not been modified from FIG. III while primed reference characters are applied to corresponding elements which have been modified.

In the structure of FIG. VI the safe edge assembly 11 is biased to extend from the leading edge of the door 9 by a combination of gravitational and spring forces much in the manner of the structure of FIG. III, the spring 40 (not shown in FIG. VI) being maintained in tension and pulling the link 33 downwardly to cause the short arm 29 of the bell crank lever 28 to pivot downwardly around pivot 32 and the longer arm 30 to pivot upwardly and outwardly. The lug 45 on the lever 28 carries its antifraction roller against the push screw 44 on the spider 42' to rotate the spider around its pivot 43 and lift the arm 62 carrying the cam roller 46. This lifting of the cam roller 46 occurs only when it is free of the ramp cams 47. The ramp cams 47 are so positioned that they initiate depression of the roller 46 as the door approaches positions where retraction of the safe edge is desired, near the fully opened and/or fully closed positions.

Thus it will be seen that the safe edge is advanced or retracted by this mechanism immediately adjacent its limits in a space within about three inches thereof, and is maintained at its full extension between those points closely adjacent the limit without any undesirable gradual extension over a first half of travel and a gradual retraction over the second half of travel. The optimum safe edge extension is maintained over essentially the entire door travel whether the cam retractor is employed alone or in combination with the cable retractor.

It is to be noted that the mechanism of this invention is so devised that while the advancement and retraction of the safe edge takes place smoothly and silently the advancement and the retraction take place during short portions of the opening and closing movements of the door so that the safe edge is in its condition of maximum advancement during most of the doors closing movement.

The forms of mechanism for advancing and retracting safe edges carried by elevator doors hereinbefore described are exemplary only. Modifications and variations within the spirit and scope of the subjoined claims are not to be regarded as a departure from the invention.

I claim: I

1. In an elevator, in combination, a car with a door having a front margin and a safe edge standing along said front margin, a pivotable spider carried by said door, means connecting said spider to said safe edge to retract said safe edge when said spider is pivoted in one direction and to pivot said spider in the opposite direction when said safe edge is advanced, yieldable means tending to advance said safe edge and means which becomes operative to pivot said spider to retract said] safe edge when said door nears its completely closed position, the means which becomes operative to pivot said spider including a cable attached to said car at one place and attached to said door at another place, and a bight which is raised as said door closes and which acts only when said door is nearly closed to pivot said spider in a direction to retract said safe edge.

2. In an elevator, in combination, a car witha door having a front margin and a safe edge standing along said front margin, a pivotable spider carried by said door, means connecting said spider to said safe edge to retract said safe edge when said spider is pivoted in one direction, an arm fixed to said spider and carrying a wheel, a cam upon which said wheel is adapted to roll to pivot said spider in the direction to retract said safe edge when said door moves to fully open position, a lever hinged to said spider, a pulley carried by said lever, a cable having a bight which takes around said pulley, the said cable being attached respectively to said door and said car whereby said bight is raised and lifts said pulley and said lever as said door closes, abutments on said lever and said spider which are engaged when said door nears closing position, whereby said spider is pivoted in the direction to retract said safe edge.

3. In an elevator, in combination, a car with a door having a front margin and a safe edge standing along said front margin, a pair of bell crank levers fulcrumed upon said door and having load pivots which connect said bell crank lever, to said safe edge, a drag link extending parallel to said safe edge and pivotally connected to said bell crank levers whereby when said drag link moves vertically said bell crank levers are rocked about their fulcra and saidrsafe edge is advanced or retracted, yieldable means tending to rock said bel-l crank levers in a direction to advance said safe edge beyond said margin of said door, a spider pivotally mounted upon said door, and means whereby pivotal movement of said spider is transmitted to said bell crank levers, a pulley, a lost motion connection between said pulley and said spider, a cable attached respectively to said car and said door, and having a bight which takes around said pulley whereby said pulley is lifted as said door closes, said lost motion connection becoming a positive connection when said door nears closed position, thereby rocking said spider in a direction to retract said safe edge.

4. In an elevator, in combination, a car with a door having a front margin, a pair of bell crank levers fulcrumed on said door and each having an upwardly extending arm, a safe edge structure standing along said front margin and pivoted at vertically separated points to said upwardly extending arms, said bell crank levers each having a rearwadly extending arm, a drag link pivotally connected at vertically separated points to said rearwardly extending arms, a spring connected to said door and said drag link and tending to lift said drag link and thereby advance said safe edge structure beyond said margin of said door, a spider pivotally mounted upon said door, said spider having a plurality of arms, a wheel mounted upon one of said arms, a cam fixed to said car in position to be engaged by said wheel as said door nears fully open position and thereby to rock said spider about its pivot, said spider carrying an adjustable push element, one of said bell crank levers carrying a projection which is pushed by said push element when said spider is rocked as said wheel rolls upon said cam, thereby swinging said bell crank levers in a direction to retract said safe edge as said door nears fully open position.

5. In an elevator, in combination, a car with a door having a front margin, a pair of bell crank levers fulcrumed on said door and each having an upwardly extending arm, a safe edge structure standing along said front margin and pivoted at vertically separated points to said upwardly extending arms, said bell crank levers each having a rearwardly extending arm, a drag link pivotally connected at vertically separated points to said rearwardly extending arms, a spring connected to said door and said drag link and tending to lift said drag link and thereby advance said safe edge structure beyond said margin of said door, a spider pivotally mounted upon said door, a lever hinged to said spider, a pulley mounted upon said lever, a cable attached to points on said door and said car and having a bight between such points, which bight takes around said pulley, whereby when said door moves in a closing direction said bight and said pulley are lifted and said lever is swung upwardly, said lever having a projection and said spider having an adjustable abutment to be engaged by said projection as said door nears closed position.

6. In an elevator, in combination, a car with a door having a front margin, a pair of bell crank levers fulcrumed on said door and each having an upwardly extending arm, a safe edge structure standing along said front margin and pivoted at vertically separated points to said upwardly extending arms, said bell crank levers each having a rearwardly extending arm, a drag link pivotally connected at vertically separated points to said rearwardly extending arms, a spring connected to said door and said drag link and tending to lift said drag link and thereby advance said safe edge structure beyond said margin of said door, a spider pivotally mounted upon said door, a lever hinged to said spider, a pulley mounted upon said lever, a cable attached to points on said door and said car and having a bight between such points, which bight takes around said pulley, whereby when said door moves in a closing direction said bight'and said pulley are lifted and said lever is swung upwardly, said lever having a projection and said spider having an adjustable abutment to be engaged by said projection as said door nears closed position, said spider having a plurality of arms, a wheel mounted upon one of said arms, a cam fixed to said car in position to be engaged by said wheel as said door nears fully open position, thereby to rock said spider about its pivot, said spider carrying an adjustable push element, one of said bell crank levers carrying a projection which is pushed by said push element when said spider is rocked as said wheel rolls uponsaid cam thereby swinging said bell crank levers in a direction to retract said safe edge as said door nears fully open position.

References Cited in the file of this patent UNITED STATES PATENTS 1,890,809 Forrnan Dec. 13, 1932 2,687,172 Norman Aug. 24, 1954 2,687,455 Norman Aug. 24, 1954 2,878,898 Kraft Mar. 24, 1959 OTHER REFERENCES German printed application 1,002,929, February 21, 1957.

:UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,040,839 June 26, 1962 Carl Panter It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 5, line 73, for "limit" read limits column 6, line 54, for "lever," read levers Signed and sealed this 19th day of March 1963,

(SEAL) Attest:

ESTON G. JOHNSON A I L- A Attesting Officer Commissioner of Patents 

